More Exceptional C++

Chapter 21. An Unmanaged Pointer Problem, Part 2: What About auto_ptr?

Difficulty: 8

Does using auto_ptr help to solve the problem in Item 20?

1. As you continue to root through the archives, you see that someone must not have liked Item 20 Example 20-2 because later versions of the files in question were changed as follows:

   // Example 21-1
   //
   // In some header file:
   void f( auto_ptr<T1>, auto_ptr<T2> );
   
   // In some implementation file:
   f( auto_ptr<T1>( new T1 ), auto_ptr<T2>( new T2 ) );
   

   What improvements does this version offer over Item 20 Example 20-2, if any? Do any exception safety problems remain? Explain.

2. Demonstrate how to write an auto_ptr_new facility that solves the safety problems in Question 1 and can be invoked as follows:

    // Example 21-2 ...